The invention relates to an electrical machine with an axis of rotation and a basic body, which contains two axial end sides and slots for accommodating electrical conductors of a winding system.
Such an electrical machine is in the form of an electric motor, for example. In order to manufacture the winding system, the basic body, which is in particular in the form of a stator or a stator laminate stack, has recently been wound with a so-called needle winder, a winding nozzle of the needle winder laying an electrical conductor in the interior of a stator bore into one of the slots and progressing in the axial direction, i.e. in the direction of the axis of rotation. The winding nozzle (=needle) is first moved a bit further outwards in the axial direction at the end side. Then, the stator laminate stack is rotated about the axis of rotation until the slot end opening of that slot appears at the level of the winding nozzle at which the electrical conductor is guided back in the opposite direction within the stator bore. The process takes place in mirror-image fashion on the opposite end side. This is repeated corresponding to the desired turns number, so that winding heads form at the two end sides.
The winding system can comprise a plurality of subwindings, which are introduced into the stator laminate stack successively with the described method. In this case, the deflection path length at the end sides when the subwindings are subsequently introduced is greater than when the subwindings are first produced. As a result, the mean coil lengths of the individual subwindings differ from one another. In addition, the amount of material used when the subwindings are introduced subsequently increases, as a result of which the individual subwindings may also have differences as regards their electrical resistance.